CROTALUS OREGONUS. 23 



Dimensions. Length of head, 9 hnes; length of body, 12^ inches; length of 

 tail, with rattles. If inches; total length, 15 inches. The specimen here described 

 had 177 broad plates on the abdomen, and 22 under the tail, and 3 large rattles. 



Habits. Nothing is known of the habits of the Crotalus Oregonus. 



Geographical Distribution. This animal was found in the country west of 

 the Rocky Mountains, on the banks of the Oregon or Columbia river. 



General Remarks. I have never seen but one specimen of this serpent, and 

 that was furnished me by the celebrated naturalist Mr. Nuttall, who procured it 

 in the Oregon territory. There can be little doubt of its being a new species, as 

 it differs from the Crotalus horridus, in wanting the black lines along the neck; — 

 from the Crotalus durissus, in not being banded; — from the Crotalus adamanteus, 

 in having white lines about the head, in the form and arrangement of its vertebral 

 spots and the number of its abdominal plates; — and from the Crotalophorus 

 tergeminus, which of all its colour most resembles, in having scales and not plates 

 on the vertex. 



N. B. — The plate was coloured from a specimen preserved in alcohol. 



